drm/amd/powerplay: avoid possible buffer overflow

Make sure the clock level enforced is within the allowed
ranges.
Signed-off-by: Evan Quan <evan.quan@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Likun Gao <Likun.Gao@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/powerplay/hwmgr/vega20_hwmgr.c

@@ -2241,6 +2241,13 @@ static int vega20_force_clock_level(struct pp_hwmgr *hwmgr,
 		soft_min_level = mask ? (ffs(mask) - 1) : 0;
 		soft_max_level = mask ? (fls(mask) - 1) : 0;
 
+		if (soft_max_level >= data->dpm_table.gfx_table.count) {
+			pr_err("Clock level specified %d is over max allowed %d\n",
+					soft_max_level,
+					data->dpm_table.gfx_table.count - 1);
+			return -EINVAL;
+		}
+
 		data->dpm_table.gfx_table.dpm_state.soft_min_level =
 			data->dpm_table.gfx_table.dpm_levels[soft_min_level].value;
 		data->dpm_table.gfx_table.dpm_state.soft_max_level =
@@ -2261,6 +2268,13 @@ static int vega20_force_clock_level(struct pp_hwmgr *hwmgr,
 		soft_min_level = mask ? (ffs(mask) - 1) : 0;
 		soft_max_level = mask ? (fls(mask) - 1) : 0;
 
+		if (soft_max_level >= data->dpm_table.mem_table.count) {
+			pr_err("Clock level specified %d is over max allowed %d\n",
+					soft_max_level,
+					data->dpm_table.mem_table.count - 1);
+			return -EINVAL;
+		}
+
 		data->dpm_table.mem_table.dpm_state.soft_min_level =
 			data->dpm_table.mem_table.dpm_levels[soft_min_level].value;
 		data->dpm_table.mem_table.dpm_state.soft_max_level =